A large South American rodent (Hydrochærus capybara) Living on the margins of lakes and rivers. It is the largest extant rodent, being about three feet long, and half that in height. It somewhat resembles the Guinea pig, to which it is related; -- called also cabiai and water hog.

The capybara (also capibara), Hydrochoerus hydrochaeris ("Water pig") is a semi-aquatic herbivorous animal, the largest of living rodents. It is endemic to most of the tropical and temperate parts of South America east of the Andes, and has been introduced to north-central Florida and possibly other subtropical regions in the United States. It is the only living member of the family Hydrochoeridae.